June 1 (Bloomberg) -- The heart of the U.S. Defense of
Marriage Act, which definines marriage as only a heterosexual
union, was ruled unconstitutional by a federal appeals court in
Boston.

Plaintiffs in Boston challenged Section 3 of the act,
claiming it was discriminatory because federal Social Security,
veterans and other benefits were denied to same-sex couples
married in Massachusetts, where such unions are legal.

“The denial of federal benefits to same-sex couples
lawfully married does burden the choice of states like
Massachusetts to regulate the rules and incidents of marriage,”
the appeals judges said in an opinion yesterday, upholding the
ruling of a lower court.

The panel is the first appellate court to have declared any
part of the federal law unconstitutional, said Kenji Yoshino, a
professor of constitutional law at New York University School of
Law in Manhattan.

The court didn’t rule that any state had to change its
definition of marriage, Yoshino said in a phone interview. “It
just said that if a state allowed same-sex marriage, then the
federal government should do what it’s traditionally done and
respect whatever definition the state has adopted of marriage.”

The judges stayed the ruling pending an anticipated
decision by the U.S. Supreme Court on this case or a similar
case. The ruling applies to four New England states and Puerto
Rico, which are covered by the circuit court’s jurisdiction.

‘Difficult’ Case

“This case is difficult because it couples issues of equal
protection and federalism with the need to assess the rationale
for a congressional statute passed with minimal hearings and
lacking in formal findings,” Judge Michael Boudin wrote in the
decision. “In addition, Supreme Court precedent offers some
help to each side, but the rationale in several cases is open to
interpretation.

‘‘We have done our best to discern the direction of these
precedents, but only the Supreme Court can finally decide this
unique case.’’

The law affects 1,000 or more ‘‘generic cross references’’
to marriage in federal laws, and could affect more than 100,000
couples, the judges said in yesterday’s opinion.

Supreme Court

The Defense of Marriage Act was signed into law by
President Bill Clinton in 1996. Massachusetts became the first
U.S. state to permit same-sex marriages in May 2004, after its
highest court ruled that gays and lesbians had a constitutional
right to wed.

After the U.S. lost its case in Massachusetts, the Obama
administration decided that Section 3 of the act was
unconstitutional and that it wouldn’t defend it in court. A
bipartisan panel of the House of Representatives voted to
intervene and defend the act.

The U.S. Supreme Court in October 2006 turned away a
challenge to the law by two gay California men after an appeals
court in San Francisco concluded that the couple lacked the
legal right to challenge the law because they hadn’t shown they
were injured by it.

A federal district judge in California in February found
that Section 3 of the act is unconstitutional and violates the
Fifth Amendment equal-protection rights of a federal court
employee who was denied health insurance coverage for her wife
that is available to other married judicial employees. That
decision has been appealed.

‘Landmark Ruling’

The ‘‘landmark ruling makes clear once again that DOMA is a
discriminatory law for which there is no justification,”
Massachusetts Attorney General Martha Coakley said in a
statement. “It is unconstitutional for the federal government
to create a system of first- and second-class marriages, and it
does harm to families in Massachusetts every day.”

The fact that the case was decided by two judges appointed
by Republican presidents -- Boudin and Juan R. Torruella -- and
one appointed by a Democratic president -- Sandra Lynch -- shows
that the “tide is really turning on this issue,” Yoshino said.

The case has a “good shot” of reaching the Supreme Court
before another case challenging California’s Proposition 8, a
voter initiative that banned same-sex couples from marrying,
Yoshino said.

An appeals court in San Francisco in a 2-1 decision in
February said that voters couldn’t deprive gay couples of the
right to marry, upholding a 2010 ruling by a federal judge that
the initiative violated equal protection rights of gay and
lesbian couples. Proponents of the law have asked a larger panel
of judges at the California appellate court to review the
ruling.

California Constitution

Proposition 8, which amended California’s constitution to
say that marriage is only between one man and one woman, was
approved by 52 percent of voters in 2008 after the California
Supreme Court legalized gay marriage earlier that year.

No states would have to change their laws if the Boston
case is affirmed by the Supreme Court, while a similar
affirmation in the California case could force all states to
legalize same-sex marriages, Yoshino said.

“If the Supreme Court grants review in that case, then
there is the potential there for the Supreme Court to say there
is a fundamental right to marry from which gay couples are being
excluded and it could flip all of the states that don’t have
same-sex marriage to require them to recognize same-sex
marriage,” he said.

The defendants in the Boston case can either ask a larger
panel of the appeals court to hear the appeal or petition
directly to the Supreme Court to listen to arguments in the
case, Yoshino said.

Legal Strategy

Paul Clement, a partner at Bancroft Pllc in Washington who
defended the DOMA law for the bipartisan panel of the House of
Representatives, said in a statement that “no decisions on
legal strategy” have been made.

“But we have always been clear we expect this matter
ultimately to be decided by the Supreme Court, and that has not
changed,” Clement said.

Six states and the District of Columbia issue marriage
licenses to same-sex couples, according to the Human Rights
Campaign -- Connecticut, Iowa, Massachusetts, New Hampshire, New
York and Vermont.

The cases are Gill v. OPM, 10-2207 and 11-2214, and
Commonwealth of Massachusetts v. U.S. Department of Health,
11-2204, U.S. Court of Appeals for the First Circuit (Boston).